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a6be0538 | 1 | /* BFD back-end for WebAssembly modules. |
250d07de | 2 | Copyright (C) 2017-2021 Free Software Foundation, Inc. |
a6be0538 PC |
3 | |
4 | Based on srec.c, mmo.c, and binary.c | |
5 | ||
6 | This file is part of BFD, the Binary File Descriptor library. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | MA 02110-1301, USA. */ | |
22 | ||
23 | /* The WebAssembly module format is a simple object file format | |
24 | including up to 11 numbered sections, plus any number of named | |
25 | "custom" sections. It is described at: | |
26 | https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md. */ | |
27 | ||
28 | #include "sysdep.h" | |
29 | #include "alloca-conf.h" | |
30 | #include "bfd.h" | |
a6be0538 PC |
31 | #include "libiberty.h" |
32 | #include "libbfd.h" | |
33 | #include "wasm-module.h" | |
34 | ||
b9b204b3 AM |
35 | #ifdef HAVE_LIMITS_H |
36 | #include <limits.h> | |
37 | #endif | |
38 | #ifndef CHAR_BIT | |
39 | #define CHAR_BIT 8 | |
40 | #endif | |
41 | ||
a6be0538 PC |
42 | typedef struct |
43 | { | |
44 | asymbol * symbols; | |
45 | bfd_size_type symcount; | |
46 | } tdata_type; | |
47 | ||
48 | static const char * const wasm_numbered_sections[] = | |
49 | { | |
50 | NULL, /* Custom section, different layout. */ | |
51 | WASM_SECTION ( 1, "type"), | |
52 | WASM_SECTION ( 2, "import"), | |
53 | WASM_SECTION ( 3, "function"), | |
54 | WASM_SECTION ( 4, "table"), | |
55 | WASM_SECTION ( 5, "memory"), | |
56 | WASM_SECTION ( 6, "global"), | |
57 | WASM_SECTION ( 7, "export"), | |
58 | WASM_SECTION ( 8, "start"), | |
59 | WASM_SECTION ( 9, "element"), | |
60 | WASM_SECTION (10, "code"), | |
61 | WASM_SECTION (11, "data"), | |
62 | }; | |
63 | ||
64 | #define WASM_NUMBERED_SECTIONS ARRAY_SIZE (wasm_numbered_sections) | |
65 | ||
66 | /* Resolve SECTION_CODE to a section name if there is one, NULL | |
67 | otherwise. */ | |
68 | ||
69 | static const char * | |
70 | wasm_section_code_to_name (bfd_byte section_code) | |
71 | { | |
72 | if (section_code < WASM_NUMBERED_SECTIONS) | |
73 | return wasm_numbered_sections[section_code]; | |
74 | ||
75 | return NULL; | |
76 | } | |
77 | ||
78 | /* Translate section name NAME to a section code, or 0 if it's a | |
79 | custom name. */ | |
80 | ||
81 | static unsigned int | |
82 | wasm_section_name_to_code (const char *name) | |
83 | { | |
84 | unsigned i; | |
85 | ||
86 | for (i = 1; i < WASM_NUMBERED_SECTIONS; i++) | |
87 | if (strcmp (name, wasm_numbered_sections[i]) == 0) | |
88 | return i; | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | /* WebAssembly LEB128 integers are sufficiently like DWARF LEB128 | |
94 | integers that we use _bfd_safe_read_leb128, but there are two | |
95 | points of difference: | |
96 | ||
97 | - WebAssembly requires a 32-bit value to be encoded in at most 5 | |
98 | bytes, etc. | |
99 | - _bfd_safe_read_leb128 accepts incomplete LEB128 encodings at the | |
100 | end of the buffer, while these are invalid in WebAssembly. | |
101 | ||
102 | Those differences mean that we will accept some files that are | |
103 | invalid WebAssembly. */ | |
104 | ||
105 | /* Read an LEB128-encoded integer from ABFD's I/O stream, reading one | |
106 | byte at a time. Set ERROR_RETURN if no complete integer could be | |
107 | read, LENGTH_RETURN to the number of bytes read (including bytes in | |
108 | incomplete numbers). SIGN means interpret the number as SLEB128. */ | |
109 | ||
110 | static bfd_vma | |
07d6d2b8 AM |
111 | wasm_read_leb128 (bfd * abfd, |
112 | bfd_boolean * error_return, | |
113 | unsigned int * length_return, | |
114 | bfd_boolean sign) | |
a6be0538 PC |
115 | { |
116 | bfd_vma result = 0; | |
117 | unsigned int num_read = 0; | |
118 | unsigned int shift = 0; | |
119 | unsigned char byte = 0; | |
b9b204b3 | 120 | unsigned char lost, mask; |
27c1c427 | 121 | int status = 1; |
a6be0538 PC |
122 | |
123 | while (bfd_bread (&byte, 1, abfd) == 1) | |
124 | { | |
125 | num_read++; | |
126 | ||
b9b204b3 | 127 | if (shift < CHAR_BIT * sizeof (result)) |
27c1c427 AM |
128 | { |
129 | result |= ((bfd_vma) (byte & 0x7f)) << shift; | |
b9b204b3 AM |
130 | /* These bits overflowed. */ |
131 | lost = byte ^ (result >> shift); | |
132 | /* And this is the mask of possible overflow bits. */ | |
133 | mask = 0x7f ^ ((bfd_vma) 0x7f << shift >> shift); | |
27c1c427 AM |
134 | shift += 7; |
135 | } | |
b9b204b3 AM |
136 | else |
137 | { | |
138 | lost = byte; | |
139 | mask = 0x7f; | |
140 | } | |
141 | if ((lost & mask) != (sign && (bfd_signed_vma) result < 0 ? mask : 0)) | |
27c1c427 | 142 | status |= 2; |
a6be0538 | 143 | |
a6be0538 | 144 | if ((byte & 0x80) == 0) |
07d6d2b8 | 145 | { |
27c1c427 | 146 | status &= ~1; |
b9b204b3 | 147 | if (sign && shift < CHAR_BIT * sizeof (result) && (byte & 0x40)) |
27c1c427 | 148 | result |= -((bfd_vma) 1 << shift); |
07d6d2b8 AM |
149 | break; |
150 | } | |
a6be0538 PC |
151 | } |
152 | ||
153 | if (length_return != NULL) | |
154 | *length_return = num_read; | |
155 | if (error_return != NULL) | |
27c1c427 | 156 | *error_return = status != 0; |
a6be0538 PC |
157 | |
158 | return result; | |
159 | } | |
160 | ||
161 | /* Encode an integer V as LEB128 and write it to ABFD, return TRUE on | |
162 | success. */ | |
163 | ||
164 | static bfd_boolean | |
165 | wasm_write_uleb128 (bfd *abfd, bfd_vma v) | |
166 | { | |
167 | do | |
168 | { | |
169 | bfd_byte c = v & 0x7f; | |
170 | v >>= 7; | |
171 | ||
172 | if (v) | |
07d6d2b8 | 173 | c |= 0x80; |
a6be0538 PC |
174 | |
175 | if (bfd_bwrite (&c, 1, abfd) != 1) | |
07d6d2b8 | 176 | return FALSE; |
a6be0538 PC |
177 | } |
178 | while (v); | |
179 | ||
180 | return TRUE; | |
181 | } | |
182 | ||
183 | /* Read the LEB128 integer at P, saving it to X; at end of buffer, | |
184 | jump to error_return. */ | |
07d6d2b8 AM |
185 | #define READ_LEB128(x, p, end) \ |
186 | do \ | |
187 | { \ | |
188 | unsigned int length_read; \ | |
189 | (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \ | |
190 | FALSE, (end)); \ | |
191 | (p) += length_read; \ | |
192 | if (length_read == 0) \ | |
193 | goto error_return; \ | |
194 | } \ | |
a6be0538 PC |
195 | while (0) |
196 | ||
197 | /* Verify the magic number at the beginning of a WebAssembly module | |
198 | ABFD, setting ERRORPTR if there's a mismatch. */ | |
199 | ||
200 | static bfd_boolean | |
201 | wasm_read_magic (bfd *abfd, bfd_boolean *errorptr) | |
202 | { | |
203 | bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
204 | bfd_byte magic[SIZEOF_WASM_MAGIC]; | |
205 | ||
206 | if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic) | |
207 | && memcmp (magic, magic_const, sizeof (magic)) == 0) | |
208 | return TRUE; | |
209 | ||
210 | *errorptr = TRUE; | |
211 | return FALSE; | |
212 | } | |
213 | ||
214 | /* Read the version number from ABFD, returning TRUE if it's a supported | |
215 | version. Set ERRORPTR otherwise. */ | |
216 | ||
217 | static bfd_boolean | |
218 | wasm_read_version (bfd *abfd, bfd_boolean *errorptr) | |
219 | { | |
220 | bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
221 | bfd_byte vers[SIZEOF_WASM_VERSION]; | |
222 | ||
223 | if (bfd_bread (vers, sizeof (vers), abfd) == sizeof (vers) | |
224 | /* Don't attempt to parse newer versions, which are likely to | |
225 | require code changes. */ | |
226 | && memcmp (vers, vers_const, sizeof (vers)) == 0) | |
227 | return TRUE; | |
228 | ||
229 | *errorptr = TRUE; | |
230 | return FALSE; | |
231 | } | |
232 | ||
233 | /* Read the WebAssembly header (magic number plus version number) from | |
234 | ABFD, setting ERRORPTR to TRUE if there is a mismatch. */ | |
235 | ||
236 | static bfd_boolean | |
237 | wasm_read_header (bfd *abfd, bfd_boolean *errorptr) | |
238 | { | |
239 | if (! wasm_read_magic (abfd, errorptr)) | |
240 | return FALSE; | |
241 | ||
242 | if (! wasm_read_version (abfd, errorptr)) | |
243 | return FALSE; | |
244 | ||
245 | return TRUE; | |
246 | } | |
247 | ||
248 | /* Scan the "function" subsection of the "name" section ASECT in the | |
249 | wasm module ABFD. Create symbols. Return TRUE on success. */ | |
250 | ||
251 | static bfd_boolean | |
252 | wasm_scan_name_function_section (bfd *abfd, sec_ptr asect) | |
253 | { | |
254 | bfd_byte *p; | |
255 | bfd_byte *end; | |
256 | bfd_vma payload_size; | |
257 | bfd_vma symcount = 0; | |
258 | tdata_type *tdata = abfd->tdata.any; | |
259 | asymbol *symbols = NULL; | |
260 | sec_ptr space_function_index; | |
1f4361a7 | 261 | size_t amt; |
a6be0538 | 262 | |
a6be0538 PC |
263 | p = asect->contents; |
264 | end = asect->contents + asect->size; | |
265 | ||
0c0adcc5 | 266 | if (!p) |
a6be0538 PC |
267 | return FALSE; |
268 | ||
269 | while (p < end) | |
270 | { | |
271 | bfd_byte subsection_code = *p++; | |
272 | if (subsection_code == WASM_FUNCTION_SUBSECTION) | |
07d6d2b8 | 273 | break; |
a6be0538 PC |
274 | |
275 | /* subsection_code is documented to be a varuint7, meaning that | |
07d6d2b8 AM |
276 | it has to be a single byte in the 0 - 127 range. If it isn't, |
277 | the spec must have changed underneath us, so give up. */ | |
a6be0538 | 278 | if (subsection_code & 0x80) |
07d6d2b8 | 279 | return FALSE; |
a6be0538 PC |
280 | |
281 | READ_LEB128 (payload_size, p, end); | |
282 | ||
0c0adcc5 | 283 | if (payload_size > (size_t) (end - p)) |
07d6d2b8 | 284 | return FALSE; |
a6be0538 PC |
285 | |
286 | p += payload_size; | |
287 | } | |
288 | ||
289 | if (p >= end) | |
290 | return FALSE; | |
291 | ||
292 | READ_LEB128 (payload_size, p, end); | |
293 | ||
0c0adcc5 | 294 | if (payload_size > (size_t) (end - p)) |
a6be0538 PC |
295 | return FALSE; |
296 | ||
297 | end = p + payload_size; | |
298 | ||
299 | READ_LEB128 (symcount, p, end); | |
300 | ||
301 | /* Sanity check: each symbol has at least two bytes. */ | |
0c0adcc5 | 302 | if (symcount > payload_size / 2) |
a6be0538 PC |
303 | return FALSE; |
304 | ||
305 | tdata->symcount = symcount; | |
306 | ||
0c0adcc5 AM |
307 | space_function_index |
308 | = bfd_make_section_with_flags (abfd, WASM_SECTION_FUNCTION_INDEX, | |
309 | SEC_READONLY | SEC_CODE); | |
a6be0538 | 310 | |
0c0adcc5 AM |
311 | if (!space_function_index) |
312 | space_function_index | |
313 | = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX); | |
a6be0538 | 314 | |
0c0adcc5 | 315 | if (!space_function_index) |
a6be0538 PC |
316 | return FALSE; |
317 | ||
1f4361a7 AM |
318 | if (_bfd_mul_overflow (tdata->symcount, sizeof (asymbol), &amt)) |
319 | { | |
320 | bfd_set_error (bfd_error_file_too_big); | |
321 | return FALSE; | |
322 | } | |
323 | symbols = bfd_alloc (abfd, amt); | |
0c0adcc5 | 324 | if (!symbols) |
a6be0538 PC |
325 | return FALSE; |
326 | ||
327 | for (symcount = 0; p < end && symcount < tdata->symcount; symcount++) | |
328 | { | |
87993319 | 329 | bfd_vma idx; |
a6be0538 PC |
330 | bfd_vma len; |
331 | char *name; | |
332 | asymbol *sym; | |
333 | ||
87993319 | 334 | READ_LEB128 (idx, p, end); |
a6be0538 PC |
335 | READ_LEB128 (len, p, end); |
336 | ||
0c0adcc5 | 337 | if (len > (size_t) (end - p)) |
07d6d2b8 | 338 | goto error_return; |
a6be0538 | 339 | |
0c0adcc5 AM |
340 | name = bfd_alloc (abfd, len + 1); |
341 | if (!name) | |
07d6d2b8 | 342 | goto error_return; |
a6be0538 PC |
343 | |
344 | memcpy (name, p, len); | |
0c0adcc5 | 345 | name[len] = 0; |
a6be0538 PC |
346 | p += len; |
347 | ||
348 | sym = &symbols[symcount]; | |
349 | sym->the_bfd = abfd; | |
350 | sym->name = name; | |
87993319 | 351 | sym->value = idx; |
a6be0538 PC |
352 | sym->flags = BSF_GLOBAL | BSF_FUNCTION; |
353 | sym->section = space_function_index; | |
354 | sym->udata.p = NULL; | |
355 | } | |
356 | ||
357 | if (symcount < tdata->symcount) | |
358 | goto error_return; | |
359 | ||
360 | tdata->symbols = symbols; | |
361 | abfd->symcount = symcount; | |
362 | ||
363 | return TRUE; | |
364 | ||
365 | error_return: | |
a6be0538 PC |
366 | bfd_release (abfd, symbols); |
367 | return FALSE; | |
368 | } | |
369 | ||
370 | /* Read a byte from ABFD and return it, or EOF for EOF or error. | |
371 | Set ERRORPTR on non-EOF error. */ | |
372 | ||
373 | static int | |
374 | wasm_read_byte (bfd *abfd, bfd_boolean *errorptr) | |
375 | { | |
376 | bfd_byte byte; | |
377 | ||
378 | if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1) | |
379 | { | |
380 | if (bfd_get_error () != bfd_error_file_truncated) | |
07d6d2b8 | 381 | *errorptr = TRUE; |
a6be0538 PC |
382 | return EOF; |
383 | } | |
384 | ||
385 | return byte; | |
386 | } | |
387 | ||
388 | /* Scan the wasm module ABFD, creating sections and symbols. | |
389 | Return TRUE on success. */ | |
390 | ||
391 | static bfd_boolean | |
392 | wasm_scan (bfd *abfd) | |
393 | { | |
394 | bfd_boolean error = FALSE; | |
395 | /* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes | |
396 | with actual data addresses. */ | |
397 | bfd_vma vma = 0x80000000; | |
398 | int section_code; | |
399 | unsigned int bytes_read; | |
a6be0538 PC |
400 | asection *bfdsec; |
401 | ||
402 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
403 | goto error_return; | |
404 | ||
0c0adcc5 | 405 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
406 | goto error_return; |
407 | ||
408 | while ((section_code = wasm_read_byte (abfd, &error)) != EOF) | |
409 | { | |
410 | if (section_code != 0) | |
07d6d2b8 AM |
411 | { |
412 | const char *sname = wasm_section_code_to_name (section_code); | |
413 | ||
0c0adcc5 | 414 | if (!sname) |
07d6d2b8 AM |
415 | goto error_return; |
416 | ||
0c0adcc5 AM |
417 | bfdsec = bfd_make_section_anyway_with_flags (abfd, sname, |
418 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
419 | if (bfdsec == NULL) |
420 | goto error_return; | |
07d6d2b8 | 421 | |
07d6d2b8 AM |
422 | bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); |
423 | if (error) | |
424 | goto error_return; | |
07d6d2b8 | 425 | } |
a6be0538 | 426 | else |
07d6d2b8 AM |
427 | { |
428 | bfd_vma payload_len; | |
07d6d2b8 | 429 | bfd_vma namelen; |
0c0adcc5 | 430 | char *name; |
07d6d2b8 | 431 | char *prefix = WASM_SECTION_PREFIX; |
0c0adcc5 | 432 | size_t prefixlen = strlen (prefix); |
2f57795b | 433 | ufile_ptr filesize; |
07d6d2b8 AM |
434 | |
435 | payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); | |
436 | if (error) | |
437 | goto error_return; | |
07d6d2b8 | 438 | namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE); |
2f57795b AM |
439 | if (error || bytes_read > payload_len |
440 | || namelen > payload_len - bytes_read) | |
07d6d2b8 | 441 | goto error_return; |
2f57795b AM |
442 | payload_len -= namelen + bytes_read; |
443 | filesize = bfd_get_file_size (abfd); | |
444 | if (filesize != 0 && namelen > filesize) | |
445 | { | |
446 | bfd_set_error (bfd_error_file_truncated); | |
447 | return FALSE; | |
448 | } | |
0c0adcc5 AM |
449 | name = bfd_alloc (abfd, namelen + prefixlen + 1); |
450 | if (!name) | |
07d6d2b8 | 451 | goto error_return; |
0c0adcc5 AM |
452 | memcpy (name, prefix, prefixlen); |
453 | if (bfd_bread (name + prefixlen, namelen, abfd) != namelen) | |
a6be0538 | 454 | goto error_return; |
0c0adcc5 | 455 | name[prefixlen + namelen] = 0; |
a6be0538 | 456 | |
0c0adcc5 AM |
457 | bfdsec = bfd_make_section_anyway_with_flags (abfd, name, |
458 | SEC_HAS_CONTENTS); | |
07d6d2b8 AM |
459 | if (bfdsec == NULL) |
460 | goto error_return; | |
a6be0538 | 461 | |
2f57795b | 462 | bfdsec->size = payload_len; |
07d6d2b8 | 463 | } |
a6be0538 | 464 | |
2f57795b AM |
465 | bfdsec->vma = vma; |
466 | bfdsec->lma = vma; | |
467 | bfdsec->alignment_power = 0; | |
468 | bfdsec->filepos = bfd_tell (abfd); | |
a6be0538 | 469 | if (bfdsec->size != 0) |
07d6d2b8 | 470 | { |
2bb3687b AM |
471 | bfdsec->contents = _bfd_alloc_and_read (abfd, bfdsec->size, |
472 | bfdsec->size); | |
0c0adcc5 | 473 | if (!bfdsec->contents) |
07d6d2b8 | 474 | goto error_return; |
07d6d2b8 | 475 | } |
a6be0538 PC |
476 | |
477 | vma += bfdsec->size; | |
478 | } | |
479 | ||
480 | /* Make sure we're at actual EOF. There's no indication in the | |
481 | WebAssembly format of how long the file is supposed to be. */ | |
482 | if (error) | |
483 | goto error_return; | |
484 | ||
485 | return TRUE; | |
486 | ||
487 | error_return: | |
a6be0538 PC |
488 | return FALSE; |
489 | } | |
490 | ||
491 | /* Put a numbered section ASECT of ABFD into the table of numbered | |
492 | sections pointed to by FSARG. */ | |
493 | ||
494 | static void | |
495 | wasm_register_section (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 | 496 | asection *asect, |
a6be0538 PC |
497 | void *fsarg) |
498 | { | |
499 | sec_ptr *numbered_sections = fsarg; | |
87993319 | 500 | int idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 501 | |
87993319 | 502 | if (idx == 0) |
a6be0538 PC |
503 | return; |
504 | ||
87993319 | 505 | numbered_sections[idx] = asect; |
a6be0538 PC |
506 | } |
507 | ||
508 | struct compute_section_arg | |
509 | { | |
510 | bfd_vma pos; | |
511 | bfd_boolean failed; | |
512 | }; | |
513 | ||
514 | /* Compute the file position of ABFD's section ASECT. FSARG is a | |
515 | pointer to the current file position. | |
516 | ||
517 | We allow section names of the form .wasm.id to encode the numbered | |
518 | section with ID id, if it exists; otherwise, a custom section with | |
519 | ID "id" is produced. Arbitrary section names are for sections that | |
520 | are assumed already to contain a section header; those are appended | |
521 | to the WebAssembly module verbatim. */ | |
522 | ||
523 | static void | |
524 | wasm_compute_custom_section_file_position (bfd *abfd, | |
525 | sec_ptr asect, | |
07d6d2b8 | 526 | void *fsarg) |
a6be0538 PC |
527 | { |
528 | struct compute_section_arg *fs = fsarg; | |
87993319 | 529 | int idx; |
a6be0538 PC |
530 | |
531 | if (fs->failed) | |
532 | return; | |
533 | ||
87993319 | 534 | idx = wasm_section_name_to_code (asect->name); |
a6be0538 | 535 | |
87993319 | 536 | if (idx != 0) |
a6be0538 PC |
537 | return; |
538 | ||
08dedd66 | 539 | if (startswith (asect->name, WASM_SECTION_PREFIX)) |
a6be0538 PC |
540 | { |
541 | const char *name = asect->name + strlen (WASM_SECTION_PREFIX); | |
542 | bfd_size_type payload_len = asect->size; | |
543 | bfd_size_type name_len = strlen (name); | |
544 | bfd_size_type nl = name_len; | |
545 | ||
546 | payload_len += name_len; | |
547 | ||
548 | do | |
07d6d2b8 AM |
549 | { |
550 | payload_len++; | |
551 | nl >>= 7; | |
552 | } | |
a6be0538 PC |
553 | while (nl); |
554 | ||
555 | bfd_seek (abfd, fs->pos, SEEK_SET); | |
556 | if (! wasm_write_uleb128 (abfd, 0) | |
07d6d2b8 AM |
557 | || ! wasm_write_uleb128 (abfd, payload_len) |
558 | || ! wasm_write_uleb128 (abfd, name_len) | |
559 | || bfd_bwrite (name, name_len, abfd) != name_len) | |
560 | goto error_return; | |
a6be0538 PC |
561 | fs->pos = asect->filepos = bfd_tell (abfd); |
562 | } | |
563 | else | |
564 | { | |
565 | asect->filepos = fs->pos; | |
566 | } | |
567 | ||
568 | ||
569 | fs->pos += asect->size; | |
570 | return; | |
571 | ||
572 | error_return: | |
573 | fs->failed = TRUE; | |
574 | } | |
575 | ||
576 | /* Compute the file positions for the sections of ABFD. Currently, | |
577 | this writes all numbered sections first, in order, then all custom | |
578 | sections, in section order. | |
579 | ||
580 | The spec says that the numbered sections must appear in order of | |
581 | their ids, but custom sections can appear in any position and any | |
582 | order, and more than once. FIXME: support that. */ | |
583 | ||
584 | static bfd_boolean | |
585 | wasm_compute_section_file_positions (bfd *abfd) | |
586 | { | |
587 | bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC; | |
588 | bfd_byte vers[SIZEOF_WASM_VERSION] = WASM_VERSION; | |
589 | sec_ptr numbered_sections[WASM_NUMBERED_SECTIONS]; | |
590 | struct compute_section_arg fs; | |
591 | unsigned int i; | |
592 | ||
593 | bfd_seek (abfd, (bfd_vma) 0, SEEK_SET); | |
594 | ||
595 | if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic) | |
596 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
597 | return FALSE; | |
598 | ||
599 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
600 | numbered_sections[i] = NULL; | |
601 | ||
602 | bfd_map_over_sections (abfd, wasm_register_section, numbered_sections); | |
603 | ||
604 | fs.pos = bfd_tell (abfd); | |
605 | for (i = 0; i < WASM_NUMBERED_SECTIONS; i++) | |
606 | { | |
607 | sec_ptr sec = numbered_sections[i]; | |
608 | bfd_size_type size; | |
609 | ||
610 | if (! sec) | |
07d6d2b8 | 611 | continue; |
a6be0538 PC |
612 | size = sec->size; |
613 | if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0) | |
07d6d2b8 | 614 | return FALSE; |
a6be0538 | 615 | if (! wasm_write_uleb128 (abfd, i) |
07d6d2b8 AM |
616 | || ! wasm_write_uleb128 (abfd, size)) |
617 | return FALSE; | |
a6be0538 PC |
618 | fs.pos = sec->filepos = bfd_tell (abfd); |
619 | fs.pos += size; | |
620 | } | |
621 | ||
622 | fs.failed = FALSE; | |
623 | ||
624 | bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs); | |
625 | ||
626 | if (fs.failed) | |
627 | return FALSE; | |
628 | ||
629 | abfd->output_has_begun = TRUE; | |
630 | ||
631 | return TRUE; | |
632 | } | |
633 | ||
634 | static bfd_boolean | |
635 | wasm_set_section_contents (bfd *abfd, | |
07d6d2b8 AM |
636 | sec_ptr section, |
637 | const void *location, | |
638 | file_ptr offset, | |
639 | bfd_size_type count) | |
a6be0538 PC |
640 | { |
641 | if (count == 0) | |
642 | return TRUE; | |
643 | ||
644 | if (! abfd->output_has_begun | |
645 | && ! wasm_compute_section_file_positions (abfd)) | |
646 | return FALSE; | |
647 | ||
648 | if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 | |
649 | || bfd_bwrite (location, count, abfd) != count) | |
650 | return FALSE; | |
651 | ||
652 | return TRUE; | |
653 | } | |
654 | ||
655 | static bfd_boolean | |
656 | wasm_write_object_contents (bfd* abfd) | |
657 | { | |
658 | bfd_byte magic[] = WASM_MAGIC; | |
659 | bfd_byte vers[] = WASM_VERSION; | |
660 | ||
661 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) | |
662 | return FALSE; | |
663 | ||
664 | if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic) | |
665 | || bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers)) | |
666 | return FALSE; | |
667 | ||
668 | return TRUE; | |
669 | } | |
670 | ||
671 | static bfd_boolean | |
672 | wasm_mkobject (bfd *abfd) | |
673 | { | |
674 | tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type)); | |
675 | ||
676 | if (! tdata) | |
677 | return FALSE; | |
678 | ||
679 | tdata->symbols = NULL; | |
680 | tdata->symcount = 0; | |
681 | ||
682 | abfd->tdata.any = tdata; | |
683 | ||
684 | return TRUE; | |
685 | } | |
686 | ||
687 | static long | |
688 | wasm_get_symtab_upper_bound (bfd *abfd) | |
689 | { | |
690 | tdata_type *tdata = abfd->tdata.any; | |
691 | ||
692 | return (tdata->symcount + 1) * (sizeof (asymbol *)); | |
693 | } | |
694 | ||
695 | static long | |
696 | wasm_canonicalize_symtab (bfd *abfd, asymbol **alocation) | |
697 | { | |
698 | tdata_type *tdata = abfd->tdata.any; | |
699 | size_t i; | |
700 | ||
701 | for (i = 0; i < tdata->symcount; i++) | |
702 | alocation[i] = &tdata->symbols[i]; | |
703 | alocation[i] = NULL; | |
704 | ||
705 | return tdata->symcount; | |
706 | } | |
707 | ||
708 | static asymbol * | |
709 | wasm_make_empty_symbol (bfd *abfd) | |
710 | { | |
986f0783 | 711 | size_t amt = sizeof (asymbol); |
a6be0538 PC |
712 | asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); |
713 | ||
714 | if (! new_symbol) | |
715 | return NULL; | |
716 | new_symbol->the_bfd = abfd; | |
717 | return new_symbol; | |
718 | } | |
719 | ||
720 | static void | |
721 | wasm_print_symbol (bfd *abfd, | |
07d6d2b8 AM |
722 | void * filep, |
723 | asymbol *symbol, | |
724 | bfd_print_symbol_type how) | |
a6be0538 PC |
725 | { |
726 | FILE *file = (FILE *) filep; | |
727 | ||
728 | switch (how) | |
729 | { | |
730 | case bfd_print_symbol_name: | |
731 | fprintf (file, "%s", symbol->name); | |
732 | break; | |
733 | ||
734 | default: | |
735 | bfd_print_symbol_vandf (abfd, filep, symbol); | |
736 | fprintf (file, " %-5s %s", symbol->section->name, symbol->name); | |
737 | } | |
738 | } | |
739 | ||
740 | static void | |
741 | wasm_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED, | |
07d6d2b8 AM |
742 | asymbol *symbol, |
743 | symbol_info *ret) | |
a6be0538 PC |
744 | { |
745 | bfd_symbol_info (symbol, ret); | |
746 | } | |
747 | ||
748 | /* Check whether ABFD is a WebAssembly module; if so, scan it. */ | |
749 | ||
cb001c0d | 750 | static bfd_cleanup |
a6be0538 PC |
751 | wasm_object_p (bfd *abfd) |
752 | { | |
753 | bfd_boolean error; | |
0c0adcc5 | 754 | asection *s; |
a6be0538 PC |
755 | |
756 | if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) | |
757 | return NULL; | |
758 | ||
0c0adcc5 | 759 | if (!wasm_read_header (abfd, &error)) |
a6be0538 PC |
760 | { |
761 | bfd_set_error (bfd_error_wrong_format); | |
762 | return NULL; | |
763 | } | |
764 | ||
0c0adcc5 | 765 | if (!wasm_mkobject (abfd)) |
a6be0538 PC |
766 | return NULL; |
767 | ||
0c0adcc5 AM |
768 | if (!wasm_scan (abfd) |
769 | || !bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0)) | |
770 | { | |
771 | bfd_release (abfd, abfd->tdata.any); | |
772 | abfd->tdata.any = NULL; | |
773 | return NULL; | |
774 | } | |
a6be0538 | 775 | |
0c0adcc5 AM |
776 | s = bfd_get_section_by_name (abfd, WASM_NAME_SECTION); |
777 | if (s != NULL && wasm_scan_name_function_section (abfd, s)) | |
a6be0538 PC |
778 | abfd->flags |= HAS_SYMS; |
779 | ||
cb001c0d | 780 | return _bfd_no_cleanup; |
a6be0538 PC |
781 | } |
782 | ||
783 | /* BFD_JUMP_TABLE_WRITE */ | |
07d6d2b8 | 784 | #define wasm_set_arch_mach _bfd_generic_set_arch_mach |
a6be0538 PC |
785 | |
786 | /* BFD_JUMP_TABLE_SYMBOLS */ | |
07d6d2b8 AM |
787 | #define wasm_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string |
788 | #define wasm_bfd_is_local_label_name bfd_generic_is_local_label_name | |
d00dd7dc | 789 | #define wasm_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false |
07d6d2b8 AM |
790 | #define wasm_get_lineno _bfd_nosymbols_get_lineno |
791 | #define wasm_find_nearest_line _bfd_nosymbols_find_nearest_line | |
792 | #define wasm_find_line _bfd_nosymbols_find_line | |
793 | #define wasm_find_inliner_info _bfd_nosymbols_find_inliner_info | |
794 | #define wasm_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol | |
795 | #define wasm_read_minisymbols _bfd_generic_read_minisymbols | |
796 | #define wasm_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol | |
a6be0538 PC |
797 | |
798 | const bfd_target wasm_vec = | |
799 | { | |
07d6d2b8 | 800 | "wasm", /* Name. */ |
a6be0538 PC |
801 | bfd_target_unknown_flavour, |
802 | BFD_ENDIAN_LITTLE, | |
803 | BFD_ENDIAN_LITTLE, | |
804 | (HAS_SYMS | WP_TEXT), /* Object flags. */ | |
805 | (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS), /* Section flags. */ | |
07d6d2b8 AM |
806 | 0, /* Leading underscore. */ |
807 | ' ', /* AR_pad_char. */ | |
808 | 255, /* AR_max_namelen. */ | |
a6be0538 | 809 | 0, /* Match priority. */ |
d1bcae83 | 810 | TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */ |
a6be0538 PC |
811 | /* Routines to byte-swap various sized integers from the data sections. */ |
812 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
813 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
814 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
815 | ||
816 | /* Routines to byte-swap various sized integers from the file headers. */ | |
817 | bfd_getl64, bfd_getl_signed_64, bfd_putl64, | |
818 | bfd_getl32, bfd_getl_signed_32, bfd_putl32, | |
819 | bfd_getl16, bfd_getl_signed_16, bfd_putl16, | |
820 | ||
821 | { | |
822 | _bfd_dummy_target, | |
823 | wasm_object_p, /* bfd_check_format. */ | |
824 | _bfd_dummy_target, | |
825 | _bfd_dummy_target, | |
826 | }, | |
827 | { | |
d00dd7dc | 828 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
829 | wasm_mkobject, |
830 | _bfd_generic_mkarchive, | |
d00dd7dc | 831 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
832 | }, |
833 | { /* bfd_write_contents. */ | |
d00dd7dc | 834 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
835 | wasm_write_object_contents, |
836 | _bfd_write_archive_contents, | |
d00dd7dc | 837 | _bfd_bool_bfd_false_error, |
a6be0538 PC |
838 | }, |
839 | ||
840 | BFD_JUMP_TABLE_GENERIC (_bfd_generic), | |
841 | BFD_JUMP_TABLE_COPY (_bfd_generic), | |
842 | BFD_JUMP_TABLE_CORE (_bfd_nocore), | |
843 | BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), | |
844 | BFD_JUMP_TABLE_SYMBOLS (wasm), | |
845 | BFD_JUMP_TABLE_RELOCS (_bfd_norelocs), | |
846 | BFD_JUMP_TABLE_WRITE (wasm), | |
847 | BFD_JUMP_TABLE_LINK (_bfd_nolink), | |
848 | BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), | |
849 | ||
850 | NULL, | |
851 | ||
852 | NULL, | |
853 | }; |